Field of the Disclosure
This disclosure relates to blue fluorescent compounds and organic light emitting devices using the same, and more particularly, to organic light emitting diode devices using blue fluorescent compounds, which make solution processing easy, as the host of an emission layer.
Discussion of the Related Art
With the development of multimedia, flat panel displays (FDPs) are becoming more and more important. Accordingly, a variety of flat panel displays such as liquid crystal display (LCDs), plasma display panels (PDPs), field emission displays (FEDs), organic light emitting diode devices, and the like are put to practical use.
Among them, an organic light emitting diode device can be formed on a flexible transparent substrate, such as plastic, can be driven at a lower voltage (below 10V) than a plasma display panel or inorganic light emitting diode display, has relatively low power consumption, and has a superior color sense. Further, the organic light emitting diode device can represent three colors of green, blue and red, and thus is drawing a great deal of attention as a next-generation full-color display device.
The organic light emitting diode device can be formed by sequentially laminating an anode, a hole injection layer, a hole transport layer, an emission layer, and electron transport layer, an electron injection layer, and a cathode. For a light-emitting material, holes injected from the anode are recombined with electrons injected from the cathode to form excitons. Singlet excitons and triplet excitons are involved in the fluorescence and phosphorescence processes, respectively. The light-emitting material may be formed by deposition or a solution process.
In the solution process, light emitting compounds are easy to prepare, but they have very low solubility in an organic solvent. That is, the host material of the emission layer is mostly made of aromatic hydrocarbon and thus has very low solubility in an organic solvent. Moreover, the efficiency and life-span of devices fabricated using the solution process are much poorer than those of devices fabricated using the deposition process. This creates the need for the development of novel solution-type host materials.